Cardiocladius sp. 1

Makarchenko, Eugenyi A., Semenchenko, Alexander A. & Palatov, Dmitry M., 2022, Chironomids are commensals of the larvae and pupae of Blephariceridae and Simuliidae from the North Caucasus (Diptera: Chironomidae: Orthocladiinae), Zootaxa 5141 (4), pp. 373-384 : 376-378

Cardiocladius sp. 1

( Figs. 7–17 )

Material examined. 4 larvae of IV instar removed from larval Blephariceridae , RUSSIA: Republic of Dagestan, Tlyaratinsky District, Greater Caucasus , Avar Koysu River basin, the left tributary of the Dzhurmut River opposite of Choroda Village , altitude 1696 m above sea level, 41º58.654’N, 46º29.865’E, 08. V.2021 ; 3 larvae of III instar and 1 larva of IV instar removed from larval Blephariceridae , the same locality, except stream on the slope of the Dzhurmut River valley near of the Salda Village , altitude 1763 m above sea level, 41º58.046’N, 46º31.029’E, 09. V.2021 . 3 larvae of IV instar removed from larval Blephariceridae , RUSSIA: Republic of North Ossetia – Alania, Alagirsky District, Greater Caucasus , Tseyskoye Gorge , Terek River basin, waterfall on the Shalatsikomdon River , altitude 1755 m above sea level, 42.79266 N, 43.920051 E, 29.VII.2021 ; 2 larvae of II instar removed from larval Blephariceridae , the same locality, except Skazdon River near the Tsey (Tseyskoe gorge) ski resort, altitude 2025 m above sea level, 42.781545 N, 43.901025 E, 29.VII.2021 .

Larva of III–IV instar (n= 9). Total length 2.6–3.2 mm. Head dark brown to black, thoracic segments greenish, abdominal segments bluish-violet.

Head. Length 295–3328 μm, width 197–213 µm. Labral setae S I– S 2 simple ( Fig. 7 ). Premandible distally with 1 wide apical tooth ( Fig. 7 ). Antenna with 5 segments; length 1–5 segments (in µm) (n=5): 39–44: 11–15: 8–9: 7: 5; AR 1.22–1.39; apex of segment 2 with large Lauterborn organs ending at base of 4 th segment; antennal blade 31 µm long, its apex reaches the base of the 5 th segment, its internal branch reaches the middle of the 3 rd segment; one large ring organs in proximal 1/3 of basal segment and one small in distal 1/3 ( Fig. 12 ). Mandible with apical tooth and 3 inner teeth ( Fig. 14 ); seta interna with long basal part (18–20 µm) and distal with 5 branches ( Fig. 15 ); seta subdentalis leaf-shaped, with pointed apex; inner margin of mandible with 2 long serrations. Mentum with 5 pairs of lateral teeth; median tooth single, truncated or trapezoidal, in 3.3–4 times wider than 2 nd lateral tooth; 1 st lateral tooth reduced and appressed to median tooth; ventromental plates large, pointed basally ( Figs. 8–10 ). Maxilla without pecten galearis.

Abdomen. Anal tubules subequal, 120–124 µm long. Posterior parapods long, 400–408 µm long ( Fig. 16 ), length/width ratio 3.5–5,7; posterior parapods length/anal tubules length 3.2–3.3. Procerci greatly reduced, hardly protruding, in the form of tubercles or incompletely sclerotized ring (as in some Diamesa ), each bearing 4 anal setae, 3 of which are 96–124 µm long and 1 is 60–84 µm long; lateral seta 20–32 µm long sits directly on body ( Fig. 17 ).

Larva of II instar (n=2). Total length 1.6–2.0 mm. Head dark brown to black, thoracic segments greenish, abdominal segments bluish-violet.

Head. Premandible distally with 1 wide apical tooth. Antenna with 5 segments; length 1–5 segments (in µm): 15–23: 9–10: 4–7: 3–4: 2–4; AR 0.83–0.92; apex of segment 2 with large Lauterborn organs ending at base of 4 th segment; apex of antennal blade reaches middle of 4 th segment, its internal branch reaches 2/3 of the 3 rd segment; one large ring organs in proximal 1/3 of basal segment ( Fig. 13 ). Mentum with 5 pairs of lateral teeth; median tooth single, truncated or trapezoidal, in 4.2–4.3 times wider than 2 nd lateral tooth; 1 st lateral tooth reduced and appressed to median tooth ( Fig. 11 ).

Abdomen. Anal tubules subequal, 56–84 µm long. Posterior parapods long, 200–280 µm long; posterior parapods length/anal tubules length 2.9–3.3. Procerci greatly reduced, hardly protruding, in the form of tubercles or incompletely sclerotized ring, each bearing 4 anal setae, 2 of which are 56–68 µm long and 2 are 28–32 µm long; lateral seta 12–14 µm long sits directly on body.

Remarks. The larvae of Cardiocladius sp. 1 , which found on blepharicerids, according to the identification key of Cranston (1982) and Schmid (1993) are closely related to C. capucinus (Zetterstedt) but without a pupa and an adult male we cannot confirm it. Also, this is not supported by the results of DNA barcoding ( Fig. 34 ). In the process of identifying the larvae of Cardiocladius sp. 1 we also used the work of Bode (1983), according to which our species could be attributed to the Eukiefferiella cyanea group. In our opinion, this group of species should be transferred from the genus Eukiefferiella to Cardiocladius .

Ecology. Chironomid larvae on blepharicerids were collected on large stones and rocks of mountain rivers and in a waterfall at a current speed of 0.6–1 m /s, at an altitude of 1696 m a.s.l. in Dagestan and 2025 m a.s.l. in North Ossetia ( Figs. 30–32 ).

Figures

FIGURE 34. Bayesian tree based on mitochondrion COI gene for obtained sequences and each available BIN number of the genus Cardiocladius Kieffer. Eukiefferiella claripennis was used as outgroup to root the tree. Bayesian posterior probabilities (PP) are given above tree nodes. Specimens obtained in this study are in bold.

FIGURES 7–17. Larva of Cardiocladius sp. 1. 7, labrum with S-setae; 8–11, mentum; 12–13, antenna; 14, mandible; 15, inner setae of mandible; 16, anal segment with procercus, posterior parapods and anal tubules; 17, procercus with anal setae.

FIGURES 30–33. Localities of Cardiocladius sp. 1 and Blephariceridae larvae (30–32), Eukiefferiella claripennis group and Simuliidae larvae with pupae (33). 30, Greater Caucasus, Tseyskoye Gorge, Terek River basin, Waterfall on the Shalatsikomdon River (Russia: Republic of North Ossetia–Alania); 31, Greater Caucasus, Skazdon River near the Tseyskoe Gorge (Russia: Republic of North Ossetia–Alania); 32, Greater Caucasus, Avar Koysu River basin, the left tributary of the Dzhurmut River opposite of Choroda Village (Russia: Republic of Dagestan); 33, Greater Caucasus, Avar Koysu River basin, left tributary of the Joahor River, 3 km upstream of its mouth on the Jurmut River (Russia: Republic of Dagestan). (Photos by D.M. Palatov).